• Decrease font size
  • Return font size to normal
  • Increase font size
U.S. Department of Health and Human Services

Post-Approval Studies (PAS)

  • Print
  • Share
  • E-mail

The FDA has the authority to require sponsors to perform a post-approval study (or studies) at the time of approval of a premarket approval (PMA), humanitarian device exemption (HDE), or product development protocol (PDP) application. Post-approval studies can provide patients, health care professionals, the device industry, the FDA and other stakeholders information on the continued safety and effectiveness (or continued probable benefit, in the case of an HDE) of approved medical devices. This database allows you to search Post-Approval Study information by applicant or device information.

Learn more...


Continuation of Premarket Cohort PAS

Suggest Enhancement / Report Issue | export reports to excelExport to Excel
Study Status Progress Adequate
Application Number P170034 / PAS001
Date Current Protocol Accepted  
Study Name Continuation of Premarket Cohort PAS
General Study Protocol Parameters
Study Design Prospective Cohort Study
Data Source New Data Collection
Comparison Group No Control
Analysis Type Descriptive
Study Population Adult: >21
Detailed Study Protocol Parameters
Study Design Description Continued follow-up PAS for the prospective, randomized, multicenter pivotal study (HORIZON Study, CP 11-001) conducted under IDE G110048 to collect additional long-term safety information. All available subjects in both the Hydrus Microstent and control groups who consented to continuation in the study will be followed 5 years postoperatively.
Sample Size Of the 556 subjects treated in this study (369 Hydrus, 187 controls), 489 subjects (334 Hydrus, 157 controls) have completed 3-year evaluations. Based on the age of the study population and other factors, it is estimated that a minimum of 70% of subjects (233 Hydrus subjects and 110 control subjects) will complete 5-year postoperative evaluations in the continuation study.

Data Collection Primary safety outcome (study eye):

Rate of occurrence of sight-threatening adverse events

Secondary safety outcomes (study eye):

Best Corrected Visual Acuity (BCVA)

Rate of occurrence of ocular adverse events

Slit lamp, gonioscopy and fundus findings

Visual field mean deviation (MD)

Central corneal thickness

Central corneal endothelial cell density (ECD)

Rate of occurrence of device malposition1

Rate of occurrence of device obstruction

Rate of occurrence of peripheral anterior synechiae (PAS)

Secondary effectiveness outcome:

Mean change in intraocular pressure (IOP)

Proportion of patients who are not using ocular hypotensive medications with a 20% or greater reduction in IOP from baseline in the HORIZON Study

1 Device malposition is considered an AE if there are associated clinical sequelae, for example: secondary surgical intervention to modify device position (i.e., repositioning or explantation), corneal endothelial touch by device, central ECL =30%, device obstruction requiring secondary surgical intervention, or chronic inflammation or irritation.

Follow-up Visits and Length of Follow-up postoperative visits at 3,4 and 5 years
Interim or Final Data Summary
Interim Safety Information The primary safety endpoint is the rate of occurrence of sight-threatening adverse events. The secondary safety endpoints are the rates of ocular adverse events (e.g., secondary surgical interventions [SSIs], significant corneal endothelial cell density [ECD] loss, device malposition and obstruction, persistent intraocular inflammation), relevant findings on slit-lamp biomicroscopy, gonioscopy, and dilated fundoscopy, visual field changes, pachymetry changes, and changes in corneal endothelial cell density.

At 48 months, the rate of SSIs to reduce intraocular pressure (IOP) was 4.6% (17/369) in the Hydrus group and 7.0% (13/187) in the control group. The rate of device obstruction (whether partial or complete) was 8.1% (30/369). There were no device explantations. The rate of peripheral anterior synechiae (PAS) formation (with or without device obstruction) was 13.6% (50/369). The rate of device malposition was 1.4% (5/369). The rate of persistent anterior uveitis (inflammation) was 0.5% (2/369) in the Hydrus group and 2.1% (4/187) in the control group.

At 48 months, the rate of significant central corneal ECD loss (=30% loss from preoperative baseline and/or ECD <1000 cells/mm2) was 18.3% (55/301) in the Hydrus group and 10.9% (15/137) in the control group. The majority of ECD loss in both groups occurred within the first 3 months postoperatively and was likely attributable to surgical trauma.

The analysis of effectiveness was based on diurnal unmedicated IOP (with medication washout where appropriate) for the 556 patients at the 24-month time point. The primary effectiveness endpoint was met, with 77.2% in the Hydrus group and 57.8% in the Control group achieving a clinically significant (greater than or equal to 20%) decrease in unmedicated mean DIOP from baseline to the hypotensive medication-free 24-month postoperative examination.

Actual Number of Patients Enrolled 556 (369 Hydrus subjects and 187 control subjects).
Actual Number of Sites Enrolled 38 Sites (26 US and 12 OUS sites)
Patient Follow-up Rate 316 Hydrus (85.6%) and 142 (75.9%) control group participants were available for 48-month follow-up analyses.
Study Strengths & Weaknesses This is a large trial with relatively little participant attrition and few missing data. The protocol did not include detailed collection of various preoperative and intraoperative factors potentially contributing to surgical trauma, so formal analyses cannot be conducted to determine the potential causes for early corneal endothelial cell loss.

Continuation of Premarket Cohort PAS Schedule

Report Schedule
Date Due
FDA Receipt
Applicant's Reporting Status
six month report 02/08/2019 02/06/2019 On Time
one year report 08/10/2019 08/09/2019 On Time
18 month report 02/08/2020 02/06/2020 On Time
two year report 08/09/2020 08/07/2020 On Time
three year report 08/09/2021    

Contact Us

Mandated Studies Program
Food and Drug Administration
10903 New Hampshire Ave.
Silver Spring, MD 20993-0002
Email: MandatedStudiesPrograms@fda.hhs.gov

Related Links